dr. vladimir frid - taucolin/research/earthqukes/workshop/11.frid.pdf · rabinovitch a., frid v....
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ELECTROMAGNETIC RADIATION IS INDUCED BY FRACTURE IN BRITTLE MATERIALS
ELECTROMAGNETIC RADIATION IS INDUCED BY FRACTURE IN ELECTROMAGNETIC RADIATION IS INDUCED BY FRACTURE IN BRITTLE MATERIALSBRITTLE MATERIALS
Frequency Wavelength
100, 000 EHz 0.003 pm10,000 EHz 0.03 pm1,000 EHz 0.3 pm100 EHz 3 pm10 EHz 30 pm1 EHz 300 pm
100 PHz 3 nm10 PHz 30 nm1 PHz 300 nm
100 THz 3 µm10 THz 30 µm1 THz 300 µm
100 GHz 3 mm10 GHz 3 cm1 GHz 30 cm
100 MHz 3 m10 MHz 30 m1 MHz 300 m100 kHz 3 km10 kHz 30 km1 kHz 300 km100 Hz 3 Mm10 Hz 30 Mm1 Hz 300 Mm
γ - rays
X- rays
Ultraviolet
InfraredVisible
Short radio waveFM, TV bands
AM broadcast bandEMREMR
Long radio waves
Frid V., Rabinovitch A. and Bahat D. 2003. Fracture induced electromagnetic radiation. J. Phys. D. 36, 1620-1628Rabinovitch A., Frid V. and Bahat D. 2002. Gutenberg-Richter type relation for laboratory fracture induced electromagnetic radiation. Physical Review E 65, 011401-011404.
Stress
EMR signal
Stress
EMR signal
1) EMR amplitude increases prior to collapse
2) EMR intensity (number of EMR events per unit time) increases
Frid V., Rabinovitch A. and Bahat D. 2003. Fracture induced electromagnetic radiation. J. Phys. D. 36, 1620-1628Rabinovitch A., Frid V. and Bahat D. 1998. Parametrization of Electromagnetic radiation pulses obtained by triaxial fracture in granite samples. Phil. Mag. Lett. 5, 289 - 293.Rabinovitch A., Frid V. and Bahat D. 1999. A note on the amplitude -frequency relation of electromagnetic radiation pulses induced by material failure, Phil. Mag. Lett. 79, 195 - 200.
-0.04
-0.02
0
0.02
0.04
9.6 10-6 9.8 10-6 1 10-5 1.02 10-5 1.04 10-5 1.06 10-5pu
sle
Volta
ge, m
V
t, sec
t0 T 2π/ω
A0 - the pulse peak amplitude
T’ - the time interval to reach pulse maximum;
ω - the frequency;
ShortShort
LengthyLengthy
3) Shape of EMR pulses changes prior to collapse;
4) The time interval to reach pulse maximum increases prior to collapse
5) The frequency of EMR pulses decreases prior to collapse
Rabinovitch A., Frid V. and Bahat D. 2002. Gutenberg-Richter type relation for laboratory fracture induced electromagnetic radiation. Physical Review E 65, 011401-011404.
6) The slope of EMR- Benioff strain release curve decreases prior to collapse;
0.0000001
0.000001
0.00001
0.0001
0.0011101001000
time to collapse event
0.0000001
0.000001
0.00001
0.0001
0.0011101001000
time to collapse event
Nucleation stage
Nucleation Nucleation stagestage
Intermediate stage
Intermediate Intermediate stagestage
Stagebefore collapse
StageStagebefore before collapsecollapse
Frid V. and K. Vozoff K. 2005. Electromagnetic radiation induced by mining rock failure. Intern. J. Coal Geology 64(1-2), 57-65
Frid V. 1998. Electromagnetic radiation method for rock and gas outburst forecast. J. Appl. Geoph. 38, 97 - 104.
Frid V. 1997. Rock-burst hazard forecast by electromagnetic radiation excited by rock fracture. J. Rock Mech. Rock Engin. 30 (4), 229-236.
Frid V. 2000. Electromagnetic radiation method water - infusion control in rockburst-prone strata, J. Appl. Geoph. 43, 5 - 13.
Frid V. 2001. Calculation of electromagnetic radiation criterion for rockbursthazard forecast in coal mines, Pure and Applied Geophysics, 158, 931-944.
2071.96
2071.98
2072
2072.02
2072.04
2072.06
2072.08
2072.1
2072.12
2072.14
2072.16
03:36:00 04:36:29 05:36:58 06:37:26 07:37:55 08:38:24 09:38:53 10:39:22 11:39:50 12:40:19 13:40:48
time
EMR
mea
n
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
Rich
ter m
egni
tude
meanRichter
EMR monitoring before roof fallEMR monitoring before roof fall
CollapsemomentCollapseCollapsemomentmoment
1) EMR amplitude increases prior to collapse
2) EMR intensity (number of EMR events per unit time) increases3) Frequency of EMR pulses decreases prior to collapse
2071.96
2071.98
2072
2072.02
2072.04
2072.06
2072.08
2072.1
2072.12
2072.14
2072.16
03:36:00 04:36:29 05:36:58 06:37:26 07:37:55 08:38:24 09:38:53 10:39:22 11:39:50 12:40:19 13:40:48
time
EMR
mea
n
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
Rich
ter m
egni
tude
meanRichter
EMR monitoring before roof fallEMR monitoring before roof fall
CollapsemomentCollapseCollapsemomentmoment
4) The slope of EMR- Benioff strain release curve decreases prior to collapse;
1000
10000
100000
1000000
1101001000
time to collapse failure, min
squa
re ro
ot o
f ene
rgy
-su
m(m
ean)
EMR induced by roof collapseEMR induced by roof collapsein minein mine
0.01
0.1
1
10
100
1000
1101001000
time to collapse event, s
A , V
EMR induced by rock EMR induced by rock compression in labcompression in lab
Six EMR indicators of an incoming collapse1) EMR amplitude increases prior to collapse
2) EMR intensity (number of EMR events per unit time) increases
3) Shape of EMR pulses changes prior to collapse;
4) The time interval to reach pulse maximum increases prior to collapse
5) The frequency of EMR pulses decreases prior to collapse
6) The slope of EMR- Benioff strain release curve decreases prior to collapse;
During the last century interest in EMR increased in connection with the problem of earthquake prognosis. Numerous investigations measured EMR anomalies prior to earthquakes and to volcanic eruptions. It was assumed that the anomalies of EMR prior to EQ were due to the formation of micro-fractures. This abnormally high EMR level occurs hours or even days before an EQ.
During the last century interest in EMR increased in connection with the problem of earthquake prognosis. Numerous investigations measured EMR anomalies prior to earthquakes and to volcanic eruptions. It was assumed that the anomalies of EMR prior to EQ were due to the formation of micro-fractures. This abnormally high EMR level occurs hours or even days before an EQ.
Parrot et al. (1993) remarked that although the existence of EMR in relation to seismic and/or volcanic activities was clear, EMR selection out of a host of artificial signals remained a significant problem.
Parrot et al. (1993) remarked that although the existence of EMR in relation to seismic and/or volcanic activities was clear, EMR selection out of a host of artificial signals remained a significant problem.
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